vowel Speech sound in which air from the lungs passes through the mouth with minimal obstruction and without audible friction, like the i in fit. The word also refers to a letter representing such a sound ( a , e, i, o, u, and sometimes y). In articulatory phonetics (see articulation), vowels are classified by tongue and lip position; for example, high vowels like the i in machine and the u in flute are both pronounced with the tongue arched high in the mouth, but in u the lips are also rounded. Single vowel sounds are monophthongs; two vowel sounds pronounced as one syllable, like the ou in round, are diphthongs.
Voyager Either of two unmanned U.S. interplanetary probes launched in 1977 to gather information about the Sun’s outer planets. Voyager 1 flew by Jupiter in 1979 and reached Saturn in 1980. Voyager 2 traveled more slowly, flying by Jupiter, Saturn, and Uranus to reach Neptune in 1989. Data and photographs from both probes revealed new details about these giant planets, their moons, and their rings. In 1998 Voyager 1 became the most distant human-made object in space (overtaking Pioneer 10). Both Voyagers were expected to remain operable through the first or second decade of the 21st century, periodically transmitting data on the HELIOPAUSE.
Voyageurs \,vwa-ya-'zh3r\ National Park National park, northern Minnesota, U.S. Located along the Canadian border, the park was estab¬
lished in 1975 and was named for the mostly French-Canadian fur-trading frontiersmen (voyageurs) of the 18th—19th centuries. It occupies an area of 217,892 ac (88,178 ha) and consists of a network of streams and lakes, the largest of which is Rainy Lake.
Voznesensky \v9z-n y i-'s y en-ske\, Andrey (Anareyevich) (b. May
12, 1933, Moscow, Russian S.F.S.R., U.S.S.R.) Russian poet. His child¬ hood experience of World War II was later vividly reflected in poems such as “Goya” (1960), one of his best- known works. He became a protege of Boris Pasternak and a star attrac¬ tion at poetry readings until a 1963 Soviet crackdown on “excessively experimental” artists and writers. He later returned to partial favour. His most characteristic poems are apo¬ litical celebrations of art, freedom, and the unrestrained human spirit. His works were collected in the bilingual An Arrow in the Wall (1987) and in On the Edge (1991).
Vuillard \vwe-'yar\, (Jean-) Edouard (b. Nov. 11, 1868, Cui- seaux, France—d. June 21, 1940, La Baule) French painter, printmaker, and decorator. With Pierre Bonnard he developed the Intimist style, char¬ acterized by small paintings of daily home life, such as Woman Sweeping
"Under the Trees," tempera on canvas panel from "Jardin de Paris," by Edouard Vuillard, c. 1894; in the Cleveland Museum of Art, Cleveland.
COURTESY OF THE CLEVELAND MUSEUM OF ART, OHIO, GIFT OF HANNA FUND
(c. 1892). He was an original member of the Nabis; his Public Gardens (1894), a series of decorative panels that use pale light and neutral colours to create a mood of restful calm, are typical of his mature work as a Nabi. He received numerous commissions to decorate public buildings, includ¬ ing murals in the Palais de Chaillot (1937) and in the League of Nations building in Geneva (1939), and also designed for the Ballets Russes.
Vulcan Ancient Roman god of fire. He was the counterpart of the Greek Hephaestus. Vulcan was especially associated with the destructive aspects of fire, such as volcanoes or conflagrations, and for this reason his temples were usually located outside the city. His chief festival, the Volcanalia, was marked by a rite in which the heads of Roman families threw fish into the fire. Often invoked to avert fire, he was addressed with epithets such as Mulciber (“Fire Allayer”).
Vulcan Hypothetical planet within the orbit of Mercury. It was predicted in 1859 by Urbain-Jean-Joseph Le Verrier (1811-77) to account for an unexplained component of the precession of Mercury’s orbit. Sightings were reported between 1859 and 1878, but these were not confirmed sub¬ sequently by observations made either during solar eclipses or when the planet was predicted to cross the Sun. The anomalies of Mercury’s orbit were later explained by Albert Einstein’s general theory of relativity.
vulcanism See volcanism
vulcanization Chemical process, discovered by Charles Goodyear (1839), by which the physical properties of natural or synthetic rubber are improved. It consists principally of heating rubber with sulfur; other sub¬ stances (accelerators, carbon black, antioxidants, etc.) are also added. The sulfur does not simply dissolve or disperse in the rubber, but rather com¬ bines chemically, mostly in the form of cross-links (bridges) between the long-chain molecules; however, the reactions are not fully understood. Vulcanized rubber has higher tensile strength and resistance to swelling and abrasion, and is elastic over a greater range of temperatures.
Vulcano \viil-'ka-no\ Island of the Eolie Islands, off northeastern Sicily, Italy. There are three volcanoes on the island, whose area is 8 sq mi (21 sq km). Although the last major eruptions were in 1888-90, one volcano is still active.
vulcanology See volcanology
Vulci Vvol-.sA Ancient Etruscan city, northwest of Rome. It grew out of a number of Villanovan villages and flourished chiefly in the 6th-4th cen¬ turies bc, largely as a result of trade and the manufacture of bronze objects, including jugs and tripods. The important centre of a large city-state, after the 6th century bc it gradually came under Roman rule. The site, exca¬ vated in the 1950s, is noted for its bronze and pottery, much of which has been found in a huge necropolis. There also are Roman ruins.
vulture A bare-headed, keen-sighted bird of prey in any of 22 species found mainly in warm regions. New World vultures (family Cathartidae, related to storks) are 24-31 in. (60-80 cm) long. Old World vultures (family Accipitridae, related to eagles) include the smallest (20 in. [50 cm] long) and the largest vulture species. The cinereous, or black, vul¬ ture ( Aegypius monachus), one of the largest flying birds, grows to about 40 in. (100 cm) long, weighs almost 30 lb (13 kg), and has a 9-ft (2.7-m) wingspan. Most species eat carrion, garbage, and excrement, but some will occasionally eat a live animal. See also condor; marabou; turkey vul¬ ture.
vulvitis \v3l-'vi-t3s\ Inflammation of the vulva (female external genita¬ lia), with red, swollen, itchy skin that may turn white, crack, or blister. The vulva provides a moist, warm breeding ground for microorganisms, particularly for yeast (see Candida) but also for other fungi, bacteria, or viruses, especially if underwear is tight, nonporous, and nonabsorbent and if hygiene is poor. Pantyhose, synthetic underwear, detergents, vaginal sprays, and deodorants may cause allergy or irritation. Drying and thin¬ ning of tissues after menopause makes them more susceptible to irritation and infection. Treatment ranges from wearing loose, absorbent cotton underwear to creams that kill the infective microorganisms.
Vychegda Vvi-chog-dsV River River, northwestern Russia. It rises on the slopes of the Timan Ridge and joins the Northern Dvina River near Kotlas. Its 702-mi (1,130-km) course is frequently marked by marshes, lakes, and sandbanks, but it is navigable for 596 mi (960 km).
Vygotsky \vi-'g6t-ske\, L(ev) S(emyonovich) (b. Nov. 5, 1896, Orsha, Russia—d. June 11, 1934, Moscow) Soviet psychologist. He stud-
© 2006 Encyclopaedia Britannica, Inc.
2018 I Vyshinsky ► Vytautas